"Westron wind," anonymous lyric

Westron wind, when will thou blow,
The small rain down can rain?
Christ if my love were in my arms
And I in my bed again.



Source of the text - Medieval English Lyrics: A Critical Anthology, edited with an introduction and notes by R.T. Davies. London: Faber and Faber, 1963, p.291

TJB: Accentual yearn. Is the speaker a sailor in the doldrums or a winter traveler? Does it matter? Either way, why is (s)he afraid of the big rain?